A new fluorescence probe for sofosbuvir analysis in dosage form and spiked human plasma.

A simple, rapid, and low-cost technique was developed to allow reliable analysis of the anti-hepatitis C drug sofosbuvir in bulk, tablet form, and spiked human plasma. This method depends on the ability of sofosbuvir to quench the fluorescence of the newly synthesized 2-amino-3-cyano-4,6-dimethylpyridine (reagent 3). Elemental analysis and spectral data were used to validate the structure of the synthesized reagent. The newly synthesized reagent exhibited a satisfactory level of fluorescence emission at 365 nm after excitation at 247 nm. All experimental variables that might affect the quenching process were analyzed and optimized. Linearity, range, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ) were all validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The concentration range was shown to be linear between 0.1 and 1.5 µg/mL. The technique was effectively utilized for sofosbuvir analysis in both its tablet dosage form and spiked human plasma, with mean percentage recoveries of 100.13 ± 0.35 and 94.26 ± 1.69, respectively.

Whiteness and greenness assessments of a sensitive HPLC method with fluorimetric detection for dapagliflozin quantitation in human plasma: Application to a healthy human volunteer.

The evident ecological impact of human actions, like air pollution, global warming, and ozone depletion, underscores the need for environmentally friendly approaches across various domains, including analytical chemistry. This study aimed to establish a validated, eco-friendly, and sustainable approach utilizing a fluorescence detector coupled with high-performance liquid chromatography for quantifying the antihyperglycemic agent dapagliflozin (DAPA), in human plasma. This method employed a C18 Microsorb MV (4.5 × 250 mm, 5 µm [particle size]) column at 40°C, with 40:60% v/v isocratic elution of acetonitrile and (0.1%) orthophosphoric acid as the mobile phase at 1 mL/min flow rate. DAPA and the internal standard demonstrated their greatest response by performing excitation at 225 nm (λex) and recording chromatograms at an emission wavelength (λem) equal to 305 nm. The presented approach demonstrated high linearity between 50 and 2000 ng/mL and full adherence to the guidelines of the US Food and Drug Administration regarding the validation of bioanalytical methods. The described technique was effectively used for quantification of DAPA in human plasma samples from a healthy male participant who received a tablet of 10 mg DAPA. Analytical Eco-Scale, Analytical GREEnness metric, and the recently created ChlorTox Scale were utilized for greenness assessment. Additionally, the "Red, Green, and Blue 12" model was used in whiteness evaluation.

Determination of linagliptin and empagliflozin by UPLC and HPTLC techniques aided by lean six sigma approach.

Two chromatographic techniques were developed and validated for simultaneous determination of the newly co-formulated antidiabetic combination linagliptin and empagliflozin in their pure form and film-coated tables. The first technique was UPLC; the separation and resolution of both analytes were achieved using a Zorbax eclipse plus C18 column applying an isocratic elution based on phosphate buffer pH 4-acetonitrile (65:35, v/v) as a running mobile phase at flow rate 1.5 ml/min and the effluent was monitored at 220 nm. Augmentation of Lean Six Sigma with UPLC and HPTLC methods had a major impact on the development of robust specifications to ensure that the quality at six sigma level has a high level of statistical confidence and target performance. On the chromatogram, empagliflozin and linagliptin appeared at retention times of 1.417 and 2.453 min, respectively. The second technique was HPTLC; both analytes were fairly well resolved and separated using a developing mobile phase composed of ethyl acetate-chloroform-acetonitrile (55:25:20 by volume). The values of retention factor (RF ) were 0.29 and 0.53 for linagliptin and empagliflozin, respectively. All variables were investigated to adjust the whole conditions.

Determination of baloxavir marboxil in pharmaceutical preparations and spiked human plasma using its quenching action on acetoxymercuric fluorescein reagent: Assessment of greenness and whiteness.

A straightforward, reliable, and cost-effective spectrofluorimetric approach has been established for the analysis of baloxavir marboxil (BXM) in raw material, tablets, as well as spiked human plasma. The approach relies on BXM's quenching impact on acetoxymercuric fluorescein (AMF) fluorescence intensity. To improve the reaction, factors such as AMF's concentration, solution's pH, diluting solvents, and reaction time were examined and optimized. Linearity, range, accuracy, precision, LOD, and LOQ were all verified in compliance with ICH criteria. The concentration range was shown to be linear between 0.2 and 2 µg/mL. The technique was effectively utilized for BXM analysis in both its tablet as well as spiked human plasma, with mean % recoveries of 101 ± 0.36 and 98.77 ± 0.65, respectively. Two assessment models (AGREE and RGB-12) were used to compare the proposed process's greenness and sustainability to four previously published chromatographic techniques. Higher green and sustainability qualities were declared by the suggested approach than by earlier ones.

Penalization and Color Code-Technical Approaches for Methods' Greenness and Whiteness Appraisal in Veterinary Medication: Assay of Toltrazuril Suspension.

BACKGROUND: Intestinal coccidiosis is a debilitating disease in poultry and livestock, leading to economic impact worldwide. Coccidiosis is prevented and treated in broilers by the inclusion of anticoccidials in feed. Toltrazuril is administered in potable water to treat coccidiosis. OBJECTIVE: Three robust analytical methods for quantitation of toltrazuril in pure and pharmaceutical formulations are developed. Furthermore, ecological metrics; either penalization- or color-code-based techniques are applied for the appraisal of assays. METHODS: Firstly, Second-Derivative (Δλ; 5 nm) spectrophotometric method; Toltrazuril is measured from peak to peak at 244-260 nm within a linearity range of 5-25 µg/mL. The second one is a high-performance thin-layer chromatography (HPTLC) analysis performed on an aluminum sheet of silica gel using ethyl acetate, methanol, ammonium chloride buffer, and water (8:1:0.5:0.5) (%V/V) as the elution phase. Toltrazuril, at a retardation factor of 0.66 ± 0.01, is linearly determined in the range of 1-9 µg/spot at 243 nm. The third one is Reversed Phase-HPLC-diode array detection, using Agilent column C18 (5 µm, 4.6 x 150 mm) in isocratic elution mode with a mobile phase of acetonitrile and water in a ratio of 80:20 (v/v), respectively, at 1 mL/min flow rate. Toltrazuril elutes at a retention time of 2.58 ± 0.1 min and is linearly determined at 243 nm in the range of 0.25-25 µg/mL. RESULTS: Calculated 2D-values and peak areas are highly correlated to their corresponding drug concentrations at coefficients; r > 0.999. All methods were ICH validated and applied to dosage form with satisfactory % recoveries (97-103%). Statistical comparisons reported one using t-test and F-test disclose insignificant variation. Examining greenness and whiteness norms, proposed methods were evaluated and ranked alongside four different reported methods. CONCLUSION: The proposed methods are green, accurate, and can be applied in routine quality control for the determination of toltrazuril in pharmaceutical formulations.

Determination of rivaroxaban by utilizing its quenching effect on acetoxymercuric fluorescein reagent in pharmaceutical preparations and in spiked biological matrices.

A simple, precise and inexpensive spectrofluorimetric method has been developed for assay of rivaroxaban raw material and its tablets. The method depends on the quenching effect of rivaroxaban on the fluorescence intensity of acetoxymercuric fluorescein (AMF). Parameters that may affect the reaction such as pH, AMF solution concentration, reaction time and diluting solvents were studied and optimized. The proposed method was applied for determination of rivaroxaban in tablets with percentage recovery of 100.4 ± 0.28, and in organic extract of spiked plasma samples with percentage recovery of 98.40 ± 1.08. The developed method was validated according to ICH guidelines in terms of accuracy, precision, linearity, range, limit of detection (LOD) and limit of quantification (LOQ).

Green and Smart Quantitative Quality Control for Veterinary Mixture of Ivermectin and Clorsulon: Ecological Evaluation of Spectral Analyses via Analytical Eco-Scale, Green Analytical Procedure Index, and Analytical GREEnness Metric Approaches.

BACKGROUND: The global financial market is still highly threatened by bovine fasciolosis, a parasitic infection that targets cattle, mainly in tropical regions. Binary combination of ivermectin (IVER) and clorsulon (CLO), in challenging concentration ratios, is typically indicated for treatment and control of fasciolosis. OBJECTIVE: The present study aims at smart simultaneous spectrophotometric assay of both compounds at their high ratio in marketed formulation and synthetic mixtures, without any prior separation. Furthermore, their greenness profile was evaluated and compared with previous reported assay methods, including the official one. METHODS: Mathematical-based proposed methods are the dual-wavelength, induced dual-wavelength, and first derivative ratio methods. Each is developed, optimized, and applied to determine simultaneously IVER and CLO at linear ranges of 1-30 and 5-40 µg/mL, respectively. They have been validated according to ICH guidelines. Statistical Student t-tests and F-tests compared the proposed methods with a USP chromatographic technique. Ecological appraisal is accomplished using three independent metrics: Analytical Eco-Scale (AES), Green Analytical Procedure Index (GAPI), and Analytical GREEnness Metric Approach (AGREE). RESULTS: Satisfactory recoveries, ICH compliance, and adherence of proposed methods to the ecological safety margin are achieved. CONCLUSIONS: Developed methods are eco-friendly and cost-effective and can accomplish a routine quantitative quality control for concurrent determination of both drugs. HIGHLIGHTS: Veterinary antimicrobials need analytical quality control using safer and green methodologies. Data manipulated spectral analyses of IVER and CLO, in a ratio of 1:10% (v/v), are developed and optimized. AES, GAPI, and AGREE approaches illustrate the high green compliance in respect to assays reported in the literature. Furthermore, the United States Pharmacopeia (USP) assay for IVER and CLO in injectable dosage form depends on analysis of each drug separately in the presence of the other drug, but it cannot determine both drugs simultaneously.

Development, validation and greenness assessment of a new electro-driven separation method for simultaneous analysis of cefixime trihydrate and linezolid in their fixed dose combination.

The establishment and validation of a straightforward, accurate, and eco-friendly capillary zone electrophoretic-diode array detection (CZE-DAD) procedure has been presented for concurrent measurement of two common antibiotics, namely, linezolid (LIN) and cefixime trihydrate (CEF), in their binary mixture or combined dosage form. The selected fused silica capillary has total and effective lengths equal to 58.5 cm and 50 cm, respectively, with a 50 µm internal diameter. Injections were performed utilizing 100 mM borate buffer at pH 10.2 as the background electrolyte (BGE) with a 15.0 s injection time. The finally utilized voltage was 30 kV. DAD was programmed to measure LIN at 250 nm and CEF at 285 nm. In less than 6 min, the two cited drugs were resolved at 2.51 and 5.47 min for LIN and CEF respectively. The introduced procedure had a linear response in the concentration range of 5-50 µg/mL for both analytes with correlation coefficients > 0.9999. Detection and quantification limits were 1.213 and 4.042 µg/mL, respectively, for LIN and 0.301 and 1.004 µg/mL, respectively, for CEF. Validation was conducted according to the International Council for Harmonization (ICH), concerning linearity, detection and quantitation limits, range, accuracy, precision, selectivity, and robustness. Precision was found acceptable due to the low relative standard deviation (RSD%) values that did not exceed 1.86% either for repeatability or for intermediate precision. Additionally, the adequately recovered concentrations and the low values of percentage relative error (Er%) provide evidence of the accuracy of the proposed method. On the other hand, the robustness of the introduced method was affirmed by the acceptable RSD% values that did not exceed 0.6% after deliberate changes in the following procedure parameters: buffer concentration, buffer pH, and wavelength. Finally, the ability of the presented method to quantify the two tested drugs in laboratory-prepared tablets was confirmed by the adequate recoveries (≥ 99%) utilizing the standard-addition procedure, along with the absence of any significant difference between the proposed method and the reference method as proven by the student's t-test and the variance-ratio F-test values that did not exceed the theoretical ones. The analytical Eco-Scale and the analytical GREEness metric (AGREE) were the tools utilized for greenness assessment. This CZE procedure is the first electro-driven separation method that was utilized for the analysis of both antibiotics in their combined laboratory-prepared tablets with no interference from the co-formulated adjuvants.

Chromatographic reversed HPLC and TLC-densitometry methods for simultaneous determination of serdexmethylphenidate and dexmethylphenidate in presence of their degradation products-with computational assessment.

Two Chromatographic methods have been established and optimized for simultaneous determination of serdexmethylphenidate (SER.DMP) and dexmethylphenidate (DMP) in the presence of their degradation products. The first method is a reversed phase high performance liquid chromatography with diode array detection (HPLC-DAD). Isocratic separation was carried out on Waters X-bridge Shield RP18 column (150×3.9×5 µm particle size) using a mixture of 5 mM phosphate buffer (pH 5.5): acetonitrile (40:60, v/v) as a mobile phase, flow rate 1 mL/min and detection at 220 nm. The second method is a thin-layer chromatography (TLC)-densitometry method using methanol: chloroform (70:30, v/v) as a mobile phase and UV scanning at 220 nm. In HPLC method, the linearity range of SER.DMP was (2.5-25 µg/mL); with LOD (0.051 µg/mL) and LOQ (0.165 µg/mL) while for DMP was (2.5-25 µg/mL); with LOD and LOQ of (0.098 µg/mL) and (0.186 µg/mL), respectively. For TLC method the sensitivity range of SER.DMP was (5-25 µg/mL), LOD was (0.184 µg/spot), while LOQ was (0.202 µg/ spot) whereas for DMP the sensitivity range was (5-25 µg/mL) with LOD of (0.115 µg/ spot) and LOQ of (0.237 µg/ spot), respectively. SER.DMP was found to be equally labile to acidic and alkaline hydrolysis, whereas DMP was sensitive to acidic hydrolysis only. Both drugs were successfully determined in presence of acidic and basic degradants by the two developed methods (stability indicating assay method). Chromatographic separation of the degradation products was carried out on TLC aluminum silica plates 60 F254, as a stationary phase, using methanol: dichloroethane: acetonitrile (60:20:20 v/v), as a mobile phase. The degradation pathway was confirmed using TLC, IR, 1H-NMR and mass spectroscopy; moreover, the separation power was correlated to the computational results by applying molecular dynamic simulation. The developed methods were validated according to the International Conference on Harmonization (ICH) guidelines demonstrating good accuracy and precision. They were successfully applied for quantitation of SER.DMP and DMP in pure and capsule forms. The results were statistically compared with those obtained by the reported method in terms of accuracy, precision and robustness, and no significant difference was found.

Comparative study of extension area based methods for spectrophotometric determination of desmopressin acetate in the presence of its acid-induced degradation products.

Desmopressin acetate (DPA) is a synthetic analogue of vasopressin used in the treatment of diabetes insipidus, bedwetting, hemophilia A, and elevated levels of urea in the blood. Sensitive and selective stability-indicating methods are needed to be developed and validated for its assay pure and pharmaceutical dosage forms in the presence of its degradation products as no method has been reported for its determination in the presence of its degradants. This work describes a comparative study of five simple stability-indicating spectrophotometric techniques for determination of DPA in presence of its acid-degradation products (acid-degradants) without prior separation. The proposed spectrophotometric techniques (First derivative, Derivative ratio, Ratio difference, Mean centering and Dual wavelength) were developed and validated according to ICH guidelines. Acid degradation was carried out with 0.1 N HCl; the acid-degradants were separated on TLC plates and the acidic degradation pathway was established by IR, H-NMR and MS techniques. The TLC method was based on the separation of DPA and its acid-induced degradation products on silica gel plates using methanol: water (80:20, v/v) as a developing system and UV detection at 254 nm. All assay suggested methods were successfully applied for quantitation of DPA in pure and tablet forms. They are specific, sensitive, precise and accurate. They showed good linearity in the concentration range of 1-14 µg/mL with good correlation coefficients, and limit of detection (LOD) of 0.304, 0.274, 0.167, 0.248 and 0.199 and limit of quantitation (LOQ) of 0.920, 0.829, 0.506, 0.751 and 0.604) for each method, respectively. These methods were successfully applied for the simultaneous determination of DPA in its pure and tablet dosage form in the presence of its acid-degradants. The results obtained were statistically comparable with those of reported HPLC assay method; no significant differences were observed with relevance to accuracy and precision. All the methods are sensitive, selective and can be used for the routine analysis of DPA in its pure and dosage forms.

Electrochemical determination of dinitolmide in poultry product samples using a highly sensitive Mn2O3/MCNTs-NPs carbon paste electrode aided by greenness assessment tools.

In this paper, chemically modified carbon paste Mn2O3/MCNTs-NPs electrode for estimation of dinitolmide (DOM) utilizing square wave voltammetry method (SWV) was developed. The study investigated the electrochemical behavior of DOM, and the morphology of the modified electrode was evaluated by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The voltammetric behavior of DOM at modified electrode was recorded at a scan rate of 100 mVs-1 against Ag/AgCl reference electrode in phosphate buffer pH 4.0 within linearity range 2-12 µM, LOQ, and LOD of 1.8 and 0.594 µM, respectively, with average % recovery of (100.89 ± 0.795). GAPI and Analytical Eco-Scale tools were applied for greenness assessment. Specificity and interference study was valid for the proposed method; allowing DOM to be determined in its acidic degradation and its major interference drug. The proposed method was successfully employed to quantify DOM in bulk powder, egg, and frozen cuts-up chicken muscle samples.

Second-derivative synchronous fluorimetry and time-programmed HPLC-fluorescence detection for simultaneous estimation of flibanserin and sitagliptin phosphate in synthetic mixtures and human plasma samples.

Diabetes Mellitus is directly related to female anaphrodesia. Female Viagra or Flibanserin (FLB), U.S. FDA approved in 2015, is specifically indicated for premenopausal Hypoactive Sexual Desire Disorder, HSDD, which is one of the primary consequences of Diabetes Mellitus. Simultaneous analysis of the concomitantly administered, FLB and oral antidiabetics, as Sitagliptin phosphate (STG), is a crucial demand to investigate mutual drug-drug interaction. The latter is responsible for uncontrolled glycaemia and higher risk of sudden hypoglycemia. Two simple, sensitive, economical and direct analytical methods, namely, Second-Derivative Synchronous Fluorimetric Spectroscopy, D2-SFS, and High Performance Liquid Chromatography with fluorimetric detection, HPLC-FD, are established for simultaneous determination of FLB and STG in their binary mixtures. First method relies on measuring D2-SFS spectra of both drugs, at Δλ = 25 nm, along linearity ranges of 0.05-1 µg/mL for both drugs. The second method is a chromatographic one with gradient elution of FLB and STG on RP-ZORBAX Eclipse C18 column (5 µm, 4.6 × 150 mm). Mobile phase; phosphate buffer: acetonitrile, pH 4.5, with a flow rate of 1 mL/min at room temperature has been used. Time programmed fluorimetric detection is optimized at λem = 305 nm for STG (0.0-5.9 min), at λem = 375 nm for FLB (6-9 min) after both excitation at λex = 257 nm, in the linear ranges of 1-40 µg/mL and 5-60 µg/mL for FLB and STG, respectively. Proposed methods have been validated according to ICH guidelines, then applied for simultaneous quantitation of FLB and STG in their laboratory-prepared mixtures and in spiked human plasma samples. Satisfactory Student's t-value and F-variance ratio have been obtained upon comparing the results of both methods.

Simultaneous determination of rosuvastatin and propranolol in their binary mixture by synchronous spectrofluorimetry.

Simultaneous determination of rosuvastatin calcium and propranolol hydrochloride using the first derivative synchronous spectrofluorimetry was described. This method involves measuring the synchronous fluorescence of both drugs in ethanol using, ∆ λ = 60 nm then the first derivative was recorded and the peak amplitudes were measured at 350 and 374 nm for rosuvastatin calcium and propranolol hydrochloride, respectively. Under the optimum conditions, the linear ranges of rosuvastatin calcium and propranolol hydrochloride were 0.2-2 µg/mL and 0.1-1 µg/mL, respectively. The method was used for quantitative analysis of the drugs in raw materials and pharmaceutical dosage form. The validity of the proposed method was assessed according to an international conference on harmonization (ICH) guidelines.